TypeError：無法讀取null的屬性“ push”

Question

我使用Angularjs和Ionic制作了Todo應用程序。 我想將某些字段保存到localStorage，但是當我單擊“保存”時，出現此錯誤。

我的代碼是：

angular.module('myApp', ['ionic'])
    .controller('myAppCtrl', function($scope){

        $scope.uuid = function(){
            return Math.floor(( 1 + Math.random()) * 0x10000)
                .toString(16)
                .substring(1);
        };

        $scope.todo = {};
        $scope.todos = {};

        //Check The Localstorage If the Todos exists
        var todos = localStorage.getItem('todos');

        if(todos !== undefined){
            $scope.todos = JSON.parse(todos);
        }

        $scope.addTodo = function($event){
            activate_page("#create_edit");
        };

        $scope.goBack = function($event){
            activate_page("#mainpage");
        };

        $scope.saveTodo = function($event){

            $scope.todo.id = $scope.uuid();
            $scope.todos.push($scope.todo);
            $scope.todo = {};
            localStorage.setItem('todos', JSON.stringify($scope.todos)); //Save 
            activate_page("#mainpage");            
        };
    });

你能幫助我嗎？ 謝謝

Answer 1

您需要像下面那樣聲明和初始化變量$ scope.todos，因為您要推送到對象而不是數組

 $scope.todos = [];

Answer 2

您嘗試push送到JSON對象，而不是數組，其定義如下：

$scope.todos = [];